Extension step-ladder



- (Hommell.)

R. vDIINGEL,

EXTENSION STEP LADDER.

. No.y 524,195. Patented Aug. 7; 1894.-

F/QJ. l A g.

whim/ww m2 ncmms Pneus ce.. PHomLmio, wasmum'ou. D. c.

PATENT OFFICE.

RUDOLPH DENGEIJ, OE BROOKLYN, NEW YORK.

EXTENSION STEP- LADDER.

SPEGIFICATION forming part of Letters Patent No. 524,195, dated Augusta,1894.

Application iledApril 6,1894. Serial No. 506.540. (No model.)

s To all whom it may concern.-

\ reference being had Be it known that I, RUDOLPH DENGEL, a citizen ofthe United States, residing at Brook'- lyn, in the county of Kings andState of New York, have invented certain new and useful Improvements inExtension Step -Ladders;

and I do declare the following to vbe a full,`

. ladders and it is designed especially for the use of electric wiremenand othersin positions impracticable for* the ordinary step-ladl der;for example, on stairways or upon sloping. zo

galleries in theaters. It is further adapted to be turned into and usedas a straight ladder. y

The invention consists essentially of three main co-operating sections,two of which are pivoted together at the ends and the third movesup anddown between the sides of the second section as more fully hereinafterde- Y scribed.A

the invention extended Y'which A is provided with Mary constructionexcept the topmost step,

In the accompanying drawings like characters represent the same parts inthe dierent views.

Figure l is anoutline perspective showing for use upon surfaces indierent planes, and Fig. 2 presents the device when turned into astraight ladder.

' A, B and C are the three main sections, of

steps of the customwhich is very much heavier and stronger than theothers. The side boards of section A are i widened from a'point near thetop upward and l 1 furnish bearings in the added width, somewhat belowthe top ofsaid side boards, for the stout pivot roll, l. With its upperends between the widened parts of the side boards of sections A, andupon the roll, 1, as a pivot there swings the section, B, havinglongitudinal slots extending through the greater'part y of thelength ofthe side boards of this section.

In the direction of their width said side boards are pierced with holesthrough whichthe eye bolts or pins, 4, pass across the said slots forthe purpose more fully explained in the fol lowing paragraphs. Section Bpossesses no steps and to preserve its rigidity two stiff cross pieces,5, connect the slotted side boards at the extreme lower ends; said crosspieces serving the additional purpose of guides for the edges of theside boards of section, C. This third section,C, is less in width thanand 6o movable between the slotted sides of said sec tion, B, and isprovided withsteps so placed, with relation to 'the side boards, thatwhen the invention is turned to form a straight ladder all the steps ofA and C willfall in practically parallel planes. Midway and lengthwiseof the step connectingthe extreme upper ends of the side boards ofsection C, and securely fastened thereto, is the thick cross bar,

3, exceeding in length the width of section C 7o by enough to passywell, through the slots in the side'boards of B.

-rGonsidering the mode of operation, section i C beingentirely inclosedwithinvB, the ladder is adapted for a level surface and theangle betweenA and Bis governedand maintained `by slotted straps, 6, one upon eachside of the ladder, pivotally attached to B and fastened by simplecrossnuts upon Aas shown at 9 in Fig'. 1. It being desired to place theladder 8o upon a stairway, section C is! dropped until such length isattained as will allow for the difference in levels of the stairs,whenthe eye-bolts, 4, are passed through the holes in the slotted sidesof B above the cross bar, 3, 85 limiting the return of C within saidsection B. The cross pieces, 5, in connection with and aided by thebearing of the ends of the cross bar, 3, against the sides of the holdthe two sections B and C in proper align` 9o ment. It being desired toturn the invention into a straight ladder, sections B and C are closedone Within the other, or partly so, and both are swung upward upon thepivot roll, l, until their edges meet the heavy step, 7, which isfashioned of such material and strength as to easily resist the pressureof said edges against it. My construction is such that the slottedstrap, 6, again becomes available and locks the ladder in its straightform by means roo of other cross nuts upon A at 8.

All the parts of my step ladder are intentionally of the simplestdescription and designed to be made of such strength as to with slots,2,

stand successfully the rough usuage to which such articles areconstantly subjected.

I am aware that step-ladders have been made adapted to be used uponstairways and inclines, and to be turned into straightladders and withsuch constructions in view- Having thus described my invention, what Iclaim, and desire t0 Secure by Letters Patent, is

l. In an extension step ladder consisting of three main sections, thesection, A, provided with steps and top-widened side boards, thesection, B, pivoted t0 A near the top and having side boards slottedlengthwise for the admission and guidance of the cross-bar, 3, attachedto the uppermost step of section, C, said section, C, movable up anddown between the slotted sides of B, said motion being limited by pins,4, transversely'piercing the side boards of B, the whole so constructedand arranged as tobe used upon levels or inclines and adapted to beturned into a straight ladder capable of variations'in lengthsubstantially as described. l

2. In an extension step-ladder the combination of the section, B, havingslotted side boards pierced with holes for the insertion of theeye-bolts and provided With the stift cross pieces, 5, as shown anddescribed, with the section, C, moving between the slotted sides olf Bsaid section C having securely fastened upon its topmost step a heavycross bar, 3, the ends of which travel in the slotted sides of B and aregoverned by said eye-bolts or pins as hereinbefore described for thepurposes set forth. I

3. In an extension step ladder consisting of three main sections, thecombination of the section, A, having side boards widened at and nearthe top and provided with steps, the topmost of said steps, '7, beingthicker and stronger than the rest and less in width than the sideboards at that point; the section, B, pivotally attached to A at 1, andpossessing side boards with lengthwise slots, 2, transverse oritices forthe insertion of pins, 4, the cross-pieces, 5, the slotted braces, G,adapted to be fastened by the cross-nuts at 8 and 9 upon A; the thirdsection, C, movable between the sides of B and provided with steps asdescribed, the cross-bar, 3, upon the uppermost of said steps,extendinginto and mov `able along slots, 2, ot section B, said motionlimited by said pins, 4, the whole constructed and arranged to be usedupon levels or inclines and as a straight ladder the length ot' whichmay be varied substantially as specified.

4. In an extension step-ladder consisting of three main sections incombination, the section A provided with steps the topmost step being ofextraordinary thickness and strength, and having side boards widenednear 'the top and pivotally attached to the scction, B, of theconstruction shown, and the section, C, provided with steps and theheavy cross bar, 3, and adapted to move between and within the slottedsides ot' section B; the whole constructed and arranged to be used uponlevel surfaces, stairways or inclines and turned into a straight laddersubstantially as shown and described. y

In testimony whereof I affix my signature in presence of two witnesses.

' RUDOLPH DENGEL. Witnesses:A

GEO. VAN BENscHo'rEn, Louis DUDLEY MARTENS.

